An oven and a toaster are an apparatus that heats up food or materials placed inside a closed or semi-closed structure. Heating with hot air is generally referred as roasting. Generally speaking, these devices perform high-temperature processing on food and materials.
The working principle of modern electric oven is to use current heating tubes (that is based Ohm's heating) to heat up the inner air and food. In the older oven, quartz tube is adopted; in the newer one, copper tube is used. In general, two copper tubes are set at the top and bottom sides of the oven. For ovens with ultra larger volume, a W-shaped tube is adopted for increasing the length of the heating tube and for enhancing the heating efficiency. Usually there is only one heating power level for such an appliance. The heating tube has only one power rating. When the desired temperature is reached in the oven, the heating tube is turned off; when the temperature in the oven drops down, the heating tube is turned on again. Thereby, the temperature in the oven is controlled at a fixed temperature through a thermostat.
The heating source of current commercial toaster oven usually suffers from low radiation energy conversion efficiency and nonuniform heating. In addition, there is no design for varying the heating pattern. Thereby, the present invention provides an oven to address the above issues. According to the Japan Patent Publication Number 2002-147762, a food cooker using laser as heating source is provided. However, it still cannot achieve partial heating as precisely as can be done by the oven provided according to the present invention.